| 1 | // RUN: %clang_cc1 -std=c++17 -verify %s |
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| 2 | |
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| 3 | template<typename T> int not_constexpr() { return T::error; } |
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| 4 | template<typename T> constexpr int is_constexpr() { return T::error; } // expected-error {{'::'}} |
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| 5 | |
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| 6 | template<typename T> int not_constexpr_var = T::error; |
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| 7 | template<typename T> constexpr int is_constexpr_var = T::error; // expected-error {{'::'}} |
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| 8 | template<typename T> const int is_const_var = T::error; // expected-error {{'::'}} |
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| 9 | template<typename T> const volatile int is_const_volatile_var = T::error; |
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| 10 | template<typename T> T is_dependent_var = T::error; // expected-error {{'::'}} |
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| 11 | template<typename T> int &is_reference_var = T::error; // expected-error {{'::'}} |
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| 12 | template<typename T> float is_float_var = T::error; |
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| 13 | |
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| 14 | void test() { |
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| 15 | // Do not instantiate functions referenced in unevaluated operands... |
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| 16 | (void)sizeof(not_constexpr<long>()); |
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| 17 | (void)sizeof(is_constexpr<long>()); |
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| 18 | (void)sizeof(not_constexpr_var<long>); |
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| 19 | (void)sizeof(is_constexpr_var<long>); |
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| 20 | (void)sizeof(is_const_var<long>); |
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| 21 | (void)sizeof(is_const_volatile_var<long>); |
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| 22 | (void)sizeof(is_dependent_var<long>); |
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| 23 | (void)sizeof(is_dependent_var<const long>); |
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| 24 | (void)sizeof(is_reference_var<long>); |
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| 25 | (void)sizeof(is_float_var<long>); |
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| 26 | |
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| 27 | // ... but do if they are potentially constant evaluated, and refer to |
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| 28 | // constexpr functions or to variables usable in constant expressions. |
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| 29 | (void)sizeof(int{not_constexpr<int>()}); |
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| 30 | (void)sizeof(int{is_constexpr<int>()}); // expected-note {{instantiation of}} |
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| 31 | (void)sizeof(int{not_constexpr_var<int>}); |
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| 32 | (void)sizeof(int{is_constexpr_var<int>}); // expected-note {{instantiation of}} |
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| 33 | (void)sizeof(int{is_const_var<int>}); // expected-note {{instantiation of}} |
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| 34 | (void)sizeof(int{is_const_volatile_var<int>}); |
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| 35 | (void)sizeof(int{is_dependent_var<int>}); |
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| 36 | (void)sizeof(int{is_dependent_var<const int>}); // expected-note {{instantiation of}} |
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| 37 | (void)sizeof(int{is_reference_var<int>}); // expected-note {{instantiation of}} |
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| 38 | (void)sizeof(int{is_float_var<int>}); // expected-error {{cannot be narrowed}} expected-note {{cast}} |
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| 39 | } |
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| 40 | |
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